The invention relates to improvements in methods of and in apparatus for convoluting strips or bands of paper or the like around rod-shaped articles, such as groups of coaxial smokers' products including plain cigarettes, cigarillos, cigars and filter mouthpieces for tobacco smoke, lead pencils, color pencils, crayons, markers and other rod-shaped stationery products and/or others. One of the presently preferred applications of such methods and uses of such apparatus is to non-movably connect to each other filter mouthpieces and plain cigarettes, cigarillos, cigars and/or other tobacco-containing articles prior to subdivision into rod-shaped filter cigarettes, cigars, cigarillos or the like.
It is known to convolute adhesive-coated uniting bands or strips (hereinafter called bands) around groups of coaxial plain cigarettes, cigars or cigarillos and filter mouthpieces, and to thereupon subdivide each of the thus obtained products into two or more filter cigarettes cigars or cigarillos. Reference may be had, for example, to commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. A machine which is used for the making of filter cigarettes or the like is known as MAX and is distributed by the assignee of the present application. The band convoluting operation in such machines is carried out in such a way that successive composite rod-shaped articles of a series of such articles are moved sideways toward and into a rolling channel. Each composite article carries an adhesive-coated uniting band which is to be convoluted around that portion or those portions of the composite rod-shaped articles where the neighboring sections or parts of the articles abut each other. If a composite article consists of two plain cigarettes of unit length and a rod-shaped filter mouthpiece of double unit length between the plain cigarettes of unit length, the uniting band is convoluted around the entire filter mouthpiece and around the adjacent inner end portions of the plain cigarettes. The thus obtained filter cigarette of double unit length is thereupon severed midway across the convoluted uniting band to yield two filter cigarettes of unit length.
One of the two surfaces bounding the rolling channel moves relative to the other surface, or both surfaces are in motion but at different speeds, so that the articles advancing through the rolling zone are caused to turn about their respective axes while moving sideways; this causes the adhesive-coated uniting bands to become convoluted around the mouthpiece of double unit length and around the adjacent inner portions of the plain cigarettes. Similar procedures can be resorted to in order to convolute uniting bands (e.g., bands carrying advertising matter) around lead pencils, crayons, color pencils, markers and other rod-shaped stationery products.
The just described methods and apparatus are further described in commonly owned U.S. patent application Ser. No. 09/481,182 which corresponds to German patent application No. 198 575 76 A1. The apparatus which is disclosed in this commonly owned US patent application employs a conveyor which advances rod-shaped articles (each of which carries an adhesive-coated flat or substantially flat uniting band, directly into the rolling channel or zone. This can cause problems as far as the quality of the ultimate products (such as filter cigarettes) is concerned. Thus, abrupt entry of composite rod-shaped articles and of the uniting bands which adhere to the articles into the inlet of the wrapping or rolling zone can affect the appearance of the ultimate products and/or the quality of the seal or seals which is or which are to be established at the junctions of plain cigarettes and filter mouthpieces in the filter cigarettes. One of the reasons is that the abrupt entry of a rod-shaped article from the region immediately preceding the rolling zone (where the articles do not turn about their respective axes) into the rolling zone where the articles are compelled to turn due to the width of the rolling zone, i.e., because the width of such rolling zone is less than the diameter of a non-deformed rod-shaped article, can result in a shifting of the rod-shaped article and the respective uniting band relative to each other.